From 1d901c3ee5965e9b3b4c33cd40942bcf9df2531a Mon Sep 17 00:00:00 2001
From: Jorgen Lundman <lundman@lundman.net>
Date: Tue, 21 Sep 2021 00:29:59 +0900
Subject: [PATCH] Upstream: unmount snapshots before destroying them on macOS

Add function zfs_destroy_snaps_nvl_os() call. The main issue is that
macOS needs to unmount any mounted snapshots before they can be
destroyed. Other platforms can handle this in the kernel, but sending
a storm of zed events to unmount seems undesirable when we can do it
in userland to start with.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Co-authored-by: ilovezfs <ilovezfs@icloud.com>
Closes #12550
---
 include/libzfs.h                      | 1 +
 lib/libzfs/libzfs.abi                 | 6 ++++++
 lib/libzfs/libzfs_dataset.c           | 5 ++++-
 lib/libzfs/os/freebsd/libzfs_compat.c | 6 ++++++
 lib/libzfs/os/linux/libzfs_util_os.c  | 6 ++++++
 5 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/libzfs.h b/include/libzfs.h
index 270f810027..c0883a9836 100644
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -650,6 +650,7 @@ _LIBZFS_H int zfs_create_ancestors(libzfs_handle_t *, const char *);
 _LIBZFS_H int zfs_destroy(zfs_handle_t *, boolean_t);
 _LIBZFS_H int zfs_destroy_snaps(zfs_handle_t *, char *, boolean_t);
 _LIBZFS_H int zfs_destroy_snaps_nvl(libzfs_handle_t *, nvlist_t *, boolean_t);
+_LIBZFS_H int zfs_destroy_snaps_nvl_os(libzfs_handle_t *, nvlist_t *);
 _LIBZFS_H int zfs_clone(zfs_handle_t *, const char *, nvlist_t *);
 _LIBZFS_H int zfs_snapshot(libzfs_handle_t *, const char *, boolean_t,
     nvlist_t *);
diff --git a/lib/libzfs/libzfs.abi b/lib/libzfs/libzfs.abi
index a2c79c8568..c5b0975258 100644
--- a/lib/libzfs/libzfs.abi
+++ b/lib/libzfs/libzfs.abi
@@ -97,6 +97,7 @@
     <elf-symbol name='zfs_destroy' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_destroy_snaps' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_destroy_snaps_nvl' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zfs_destroy_snaps_nvl_os' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_expand_proplist' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_foreach_mountpoint' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_get_all_props' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -4161,6 +4162,11 @@
       <parameter type-id='95e97e5e' name='len'/>
       <return type-id='95e97e5e'/>
     </function-decl>
+    <function-decl name='zfs_destroy_snaps_nvl_os' mangled-name='zfs_destroy_snaps_nvl_os' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_destroy_snaps_nvl_os'>
+      <parameter type-id='b0382bb3' name='hdl'/>
+      <parameter type-id='5ce45b60' name='snaps'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='libzfs_error_init' mangled-name='libzfs_error_init' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='libzfs_error_init'>
       <parameter type-id='95e97e5e' name='error'/>
       <return type-id='80f4b756'/>
diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 20251e9e7a..fb337ca3f0 100644
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -3884,10 +3884,13 @@ zfs_destroy_snaps(zfs_handle_t *zhp, char *snapname, boolean_t defer)
 int
 zfs_destroy_snaps_nvl(libzfs_handle_t *hdl, nvlist_t *snaps, boolean_t defer)
 {
-	int ret;
 	nvlist_t *errlist = NULL;
 	nvpair_t *pair;
 
+	int ret = zfs_destroy_snaps_nvl_os(hdl, snaps);
+	if (ret != 0)
+		return (ret);
+
 	ret = lzc_destroy_snaps(snaps, defer, &errlist);
 
 	if (ret == 0) {
diff --git a/lib/libzfs/os/freebsd/libzfs_compat.c b/lib/libzfs/os/freebsd/libzfs_compat.c
index 4d7421df8d..2c9d52bb0f 100644
--- a/lib/libzfs/os/freebsd/libzfs_compat.c
+++ b/lib/libzfs/os/freebsd/libzfs_compat.c
@@ -267,6 +267,12 @@ find_shares_object(differ_info_t *di)
 	return (0);
 }
 
+int
+zfs_destroy_snaps_nvl_os(libzfs_handle_t *hdl, nvlist_t *snaps)
+{
+	return (0);
+}
+
 /*
  * Attach/detach the given filesystem to/from the given jail.
  */
diff --git a/lib/libzfs/os/linux/libzfs_util_os.c b/lib/libzfs/os/linux/libzfs_util_os.c
index b116f92d97..2ac31f1077 100644
--- a/lib/libzfs/os/linux/libzfs_util_os.c
+++ b/lib/libzfs/os/linux/libzfs_util_os.c
@@ -184,6 +184,12 @@ find_shares_object(differ_info_t *di)
 	return (0);
 }
 
+int
+zfs_destroy_snaps_nvl_os(libzfs_handle_t *hdl, nvlist_t *snaps)
+{
+	return (0);
+}
+
 /*
  * Fill given version buffer with zfs kernel version read from ZFS_SYSFS_DIR
  * Returns 0 on success, and -1 on error (with errno set)